Method of Cleaning Using An Anti-Microbial Nonwoven Wipe

ABSTRACT

The present invention is directed to a method of cleaning a hard surface with a nonwoven anti-microbial hard surface wipe, and more specifically to an anti-microbial hard surface wipe that more readily releases a disinfectant or anti-microbial agent, that includes coating a nonwoven wipe having a fibrous nonwoven substrate with a non-ionic and cationic binder mixture to provide a first coated nonwoven wipe, coating the first coated nonwoven wipe with a cationic dual quaternary ammonia anti-microbial agent to provide a second coated nonwoven wipe, providing a water source, and introducing the second coated nonwoven wipe to the water source wherein the cationic dual quaternary ammonia anti-microbial agent is readily released upon the second coated nonwoven wipe being introduced to the water source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Patent Application No.10/699,425, filed Oct. 31, 2003 (now allowed), which in turn claimspriority to U.S. Provisional Patent Application No. 60/422,786, filed onOct. 31, 2002, which are hereby incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present invention generally relates to a method of cleaning a hardsurface with a nonwoven anti-microbial hard surface wipe, and morespecifically to an anti-microbial hard surface wipe that more readilyreleases a disinfectant or anti-microbial agent.

BACKGROUND OF THE INVENTION

Over the years, the use of disposable substrates in cleaningapplications has been well practiced. Suitable substrates have includedsponges, woven and nonwoven fabrics, and various combinations thereof.Further, such substrates have been impregnated with cleaning agents suchas disinfectants, solvents, anti-microbials, detergents and otherchaotropes. The resulting cleaning products fabricated from suchimpregnated substrates have found acceptance with the general public asa convenient and practical means for the cleaning of surfaces. Inparticular, such constructs have been successful in the consumer wipesmarkets as hard surface wipes.

Nonwoven fabrics are used in a wide variety of wipe applications wherethe engineered qualities of the fabrics can be advantageously employed.The use of selected thermoplastic polymers in the construction of thefibrous fabric component, selected treatment of the fibrous component(either while in fibrous form or in an integrated structure), andselected use of various mechanisms by which the fibrous component isintegrated into a useful fabric, are typical variables by which toadjust and alter the performance of the resultant nonwoven fabric.

For the purpose of fabricating a hard surface wipe for the food serviceor hospitality industry, it is advantageous to utilize a limited orsingle use nonwoven wipe to prevent the build up of bacteria that tendsto accumulate within a standing damp sponge or terry cloth towel. Uponrepeated use of a standing damp sponge, it is more likely that bacteriawill be introduced into an area where food is prepared. Often, for thesake of convenience, the nonwoven wipe is impregnated or coated with ananti-microbial agent or disinfectant so as to prevent the growth ofbacteria and disinfect food preparation areas. It has been found,however that nonwoven hard surface wipes that are impregnated or coatedwith an anti-microbial do not readily release the anti-microbial agentdue to the affinity of the disinfectant for the nonwoven substrateitself, the binders utilized within the substrate, or the affinity forany other additives that may be present in the substrate.

The use of homogenous cationic binder in sanitation wipes has adeleterious affect on the sanitation process. Cationic binders areattracted or have a high affinity for an anionic charged disinfectantand results in a hard surface wipe that retains the disinfectant. Thedisinfectant solution is more rapidly absorbed into the wipe, whichprematurely depletes the disinfectant solution of the anti-microbialattributes. Further, a wipe comprising a cationic binder may notproperly absorb a cationic disinfectant due to the lack of affinity ofthe binder for the disinfectant. A nonwoven wipe that fails to absorbthe disinfectant solution may not effectively sanitize a given surface.

Non-ionic binders do not have an associated positive or negative chargeand are therefore compatible with various disinfecting or anti-microbialsanitizing systems. A hard surface wipe comprised of a non-ionic binderhas a low affinity for an ionic disinfecting solution, which isbeneficial to the sanitizing process. The wipe forms weak bonds with thedisinfectant, thereby increasing the life of the sanitizing solution.There remains an unmet need for a hard surface wipe that is compatiblewith various ionic disinfecting solutions.

SUMMARY OF THE INVENTION

The present invention is directed to a method of cleaning a hard surfacewith a nonwoven anti-microbial hard surface wipe, and more specificallyto an anti-microbial hard surface wipe that more readily releases adisinfectant or anti-microbial agent.

The anti-microbial wipe of the invention is a nonwoven substrate.Suitable substrates include, but are not limited to hydroentangled,airlaid, spunbond, and coform substrates. Further, the nonwovensubstrate could be a laminate or composite structure. The nonwoven wipemay be hydroentangled on a three-dimensional image transfer device inorder to impart an aesthetically appealing pattern or image into thewipe, wherein the pattern or image may or may not include apertures.Further, the wipe may include a three-dimensional image of a restaurantor hospitality industry company logo.

In a first embodiment, the nonwoven substrate used in the method of thepresent invention is comprised of a non-ionic binder, as well as acationic disinfectant. The wipe is introduced into a water source andthe disinfectant is readily released from the wipe so as to form adisinfectant solution.

In a second embodiment, the nonwoven substrate used in the method of thepresent invention is comprised of a non-ionic binder and used along witha separate commercially available disinfecting or sanitizing solution.The disinfecting solution is preferably a cationic disinfectingsolution, such as a cationic dual quaternary sanitizing system.

The hard surface wipe comprised of a non-ionic binder has a low affinityfor a cationic disinfecting solution and the weak bonds formed areeasily broken. The resulting wipe more readily releases the disinfectantinto a water source and will not attract and retain a chargeddisinfectant that could possibly prematurely deplete the effectivenessof a sanitizing solution.

DETAILED DESCRIPTION

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawing, and will hereinafter be described,a presently preferred embodiment, with the understanding that thepresent disclosure is to be considered as an exemplification of theinvention, and is not intended to limit the invention to the specificembodiment illustrated.

The present invention is directed to a method of cleaning a surface withan anti-microbial nonwoven wipe with a more readily releasabledisinfecting or anti-microbial agent. The nonwoven wipe is comprised ofa matrix of fibers or filaments that is consolidated into a nonwovenweb. In a preferred embodiment, the nonwoven wipe is a hydroentangledsubstrate. With reference to FIG. 1, therein is illustrated an apparatusfor practicing the present invention by forming a hydroentanglednonwoven fabric. The fabric is formed from a fibrous matrix, whichtypically comprises staple length fibers, but may comprise substantiallycontinuous filaments. The fibrous matrix is preferably carded andcross-lapped to form a fibrous batt. In a current embodiment, thefibrous batt comprises 100% cross-lap fibers, that is, all of the fibersof the web have been formed by cross-lapping a carded web so that thefibers are oriented at an angle relative to the machine direction of theresultant web. U.S. Pat. No. 5,475,903, hereby incorporated byreference, illustrates a web drafting apparatus.

Alternately, the fabric of the present invention may comprise anoptional support layer or scrim, wherein the fibrous web can be placedface-to-face with the support layer and hydroentangled to form precursorweb P. It is within the purview of the present invention that a scrimcan be interposed in the formation of the precursor nonwoven web. Thepurpose of the scrim is to reduce the extensibility of the resultantthree-dimensional imaged nonwoven fabric, thus reducing the possibilityof three-dimensional image distortion and further enhancing fabricdurability. Suitable scrims include unidirectional monofilament,bi-directional monofilament, expanded films, and thermoplastic spunbond.

Further, the composite construct may optionally be subsequentlysubjected to a three-dimensional image transfer device so as to impart athree-dimensional image, which may or may not include apertures.

FIG. 1 illustrates a hydroentangling apparatus for forming nonwovenfabrics in accordance with the present invention. The apparatus includesa foraminous-forming surface in the form of belt 10 upon which thefibrous web P is positioned for entangling by entangling manifold 12.Further entanglement of the web is effected on the foraminous formingsurface of a drum 18 by entanglement manifold 20, with the websubsequently passed over successive foraminous drums 20, for successiveentangling treatment by entangling manifolds 24, 24′.

The entangling apparatus of FIG. 1 further includes a three-dimensionalimaging drum 24, which can be optionally utilized, comprising athree-dimensional image transfer device for effecting imaging of thenow-entangled precursor web. The image transfer device includes amoveable imaging surface which moves relative to a plurality ofentangling manifolds 26 which act in cooperation with three-dimensionalelements defined by the imaging surface of the image transfer device toeffect imaging and patterning of the fabric being formed.

Manufacture of a nonwoven wipe embodying the principles of the presentinvention is initiated by providing the fibrous matrix, which caninclude the use of staple length fibers, continuous filaments, and theblends of fibers and/or filaments having the same or differentcomposition. Fibers and/or filaments are selected from natural orsynthetic composition, of homogeneous or mixed fiber length. Suitablenatural fibers include, but are not limited to, cotton, wood pulp andviscose rayon. Synthetic fibers, which may be blended in whole or part,include thermoplastic and thermoset polymers. Thermoplastic polymerssuitable for blending with dispersant thermoplastic resins includepolyolefins, polyamides and polyesters. The thermoplastic polymers maybe further selected from homopolymers, copolymers, conjugates and otherderivatives including those thermoplastic polymers having incorporatedmelt additives or surface-active agents. Staple lengths are selected inthe range of 0.25 inch to 10 inches, the range of 1 to 3 inches beingpreferred and the fiber denier selected in the range of 1 to 22, therange of 1.2 to 6 denier being preferred for general applications. Theprofile of the fiber and/or filament is not a limitation to theapplicability of the present invention.

It is also within the purview of the present invention that the hardsurface wipe comprise additional fabric layers so as to form a laminateconstruct. The additional layers may include, but are not limited tofabrics comprised of natural, synthetic fibers, or a combinationthereof. Suitable natural fibers include, but are not limited to,cotton, wood pulp and viscose rayon. Synthetic fibers, which may beblended in whole or part, include thermoplastic and thermoset polymers.The thermoplastic polymers may be further selected from homopolymers;copolymers, conjugates and other derivatives including thosethermoplastic polymers having incorporated melt additives orsurface-active agents. Additionally, film layers may be added to form alaminate construct. Various film layers may include, cast films,extruded films, and reticulated films.

In one embodiment, subsequent to the nonwoven web formation, the web istreated with a binder, as well as an anti-microbial or disinfectingagent. The binder of the invention is a non-ionic binder or a mixture ofa non-ionic and a cationic binder. The binder, as well as theanti-microbial cleaning agent may be applied utilizing varioustechniques known in the art, including, but not limited to impregnating,padding, spray coating, or kiss coating.

In another embodiment, the hard surface wipe is comprised of a non-ionicbinder to be utilized with a separate commercially availabledisinfecting or anti-microbial solution. The wipe of the invention ismore compatible with such solutions and will not retain theanti-microbial solution within the wipe, which could result inprematurely depleting the effectiveness of the disinfection solution.

Optionally, the anti-microbial nonwoven wipe may further include anadditive or combination of additives, such as pigments, colorstabilizers, softeners, fragrances, lotions, and other performance oraesthetic enhancers.

From the foregoing, numerous modifications and variations can beeffected without departing from the true spirit and scope of the novelconcept of the present invention. It is to be understood that nolimitation with respect to the specific embodiments disclosed herein isintended or should be inferred. The disclosure is intended to cover, bythe appended claims, all such modifications as fall within the scope ofthe claims.

1. A method of cleaning a hard surface, comprising the steps of: coatinga nonwoven wipe comprising a fibrous nonwoven substrate with a non-ionicbinder and cationic binder mixture to provide a first coated nonwovenwipe; coating the first coated nonwoven wipe with a cationic dualquaternary ammonia anti-microbial agent to provide a second coatednonwoven wipe; providing a water source; and introducing said secondcoated nonwoven wipe to said water source wherein said cationic dualquaternary ammonia anti-microbial agent being readily released into saidwater source.
 2. The method of claim 1, wherein said non-ionic binderexhibits a low affinity for said dual quaternary ammonia anti-microbialagent.
 3. The method of claim 1, wherein said fibrous nonwoven substratecomprises natural fibers.
 4. The method of claim 1, wherein said fibrousnonwoven substrate comprises natural fibers selected from the groupconsisting of cotton, wood pulp and viscose rayon.
 5. The method ofclaim 1, wherein said fibrous nonwoven substrate comprises carded andcross-lapped staple length fibers.
 6. The method of claim 1, wherein thefibrous nonwoven substrate comprises a three-dimensionally imagedfibrous nonwoven substrate.
 7. The method of claim 6, wherein thenonwoven wipe further comprises a scrim layer reducing the extensibilityof said three-dimensionally imaged fibrous nonwoven substrate.
 8. Themethod of claim 6, wherein said scrim layer is selected from aunidirectional filament scrim, a bi-directional filament scrim, anexpanded film, and a thermoplastic spunbond.
 9. The method of claim 1,wherein the nonwoven wipe comprises an additional layer selected fromthe group consisting of a fabric layer and a film layer.
 10. The methodof claim 9, wherein said additional layer is a film layer selected fromthe group consisting of a cast film, an extruded film, and a reticulatedfilm.
 11. The method of claim 1, further comprising cleaning a hardsurface with said wipe after said introducing of said second coatednonwoven wipe to said water source.